Neoview Workload Management Services Guide (R2.3)

higher priority services are currently executing, the queries associated with the lower priority
service execute next, provided that the system resource usage has not reached its limits.
WMS throttles incoming queries (that is, puts them into a waiting queue) when the system
resource usage reaches its limits. To determine available CPU and memory resources for the
system, WMS looks at a moving average every five seconds for six intervals of CPU busy and
takes a snapshot every five seconds of memory usage on the system. By default, the system
resource thresholds are a maximum CPU busy of 100% and a maximum memory usage of 85%.
However, you can change those system resource thresholds either at the WMS level by altering
WMS or at the service level by adding or altering a user-defined service. A user-defined service's
thresholds override the thresholds of the WMS system configuration. The thresholds of the WMS
system configuration override the internal default thresholds.
Service Priority Weights
WMS assigns weights to each service priority:
WeightService Priority
6URGENT
5HIGH
4MEDIUM-HIGH
3MEDIUM
2LOW-MEDIUM
1LOW
Calculation of Expected Query Execution Percentage
WMS determines an expected percentage of executing queries for each service based on the
service's priority weight:
Expected-percentage = (priority-weight / total-weight) * 100
The priority-weight is the weight of the service. For example, a service with a HIGH priority
has a priority-weight of 5. The total-weight is the sum of the weights of all active services.
For example, if there are three active services that have HIGH, MEDIUM, and LOW priorities,
the total-weight is the sum of 5 + 3 + 1, which is 9. The expected percentage for a service
with a HIGH priority is 5/9 * 100, which is 56%.
Example 1: How Service Priorities and System Resource Thresholds Work
Suppose that you have these service levels:
Expected Percentage Based on Priority WeightPriorityService Name
5/9 * 100 = 56%HIGHSERVICE1
3/9 * 100 = 33%MEDIUMSERVICE2
1/9 * 100 = 11%LOWSERVICE3
26 Configuring WMS